Heat-exchange device for treating milk, worts, and the like



M. GRUBENMANN. HEAT EXCHANGE DEVICE FOR TREATING MILK, WORTS, AND THE LIKE. APPLICATION FILED JULY5, 1921.

1,423,794, Patented Jul 25, 1922 2 SHEETS-SHEET l.

M. GRUBENMANN. HEAT EXCHANGE DEVICE FOR TREATING MILK, WORT$,'AND THE LIKE.

" APPLICATION FILED IULYS, 1921.

1 ,%23,?9%, Patented July 25, 1922.

2 SHEETS-SHEET Z.

MAX GRUIBENMANN, 0 F ZURICH,

PATENT OFFICE.

SWITZERLAND, ASSIGNOB, TO ALUMINUM- SCHWEISSWEB/K A.-G., OF SCHLIEREN, SVIITZERLAND.

HEAT-EXCHANGE DEVICE FOR TREATING MILK, WORTS,

Application filed Julyi, 1921. Serial No. 482,511.

To all whom it may concern:

Be it known that I, MAX. GRUBENMANN,

residing at Zurich Hirschengraben 60, Zu-v rich, Switzerland, have invented a new and useful Improvement in Heat-Exchange Devices for Treating Milk, Worts, and the like, of which the following is aspecification.

This invention relates to improvements in the construction of heat exchange devices for milk, worts and the like, of the type in which the liquid to be cooled flows downwards as a film over the exterior surfaces of two sheets of metal, spaced a short distance apart, while the cooling liquid, such as water or brine, flows through the space between the plates.

The metal aluminium, owing to its high heat conductivity and the absence of any deleterious action upon liquids of the kind referred to, would appear to be a highly suitable material for the construction of such heat exchange devices, but its employment has hitherto been prevented by the peculiar difliculties in working the metal. For the treatment of milk and other liquids liable to putrefactive or other changes due to the activity of micro-organisms, it is essential that flanged or rivetted joints or any construction affording crevices for the lodgment of micro-organisms should be avoided, whilst the use of solder is prohibited by the danger of contamination of food products with lead, as well as by the comparative weakness of the joints and the tendency to electrolytic action. For, these reasons autogenous welding has been. the only method which could be contemplated for the con struction of such apparatus; but the hitherto insuperable difficulty in satisfactorily welding together the edges of the two sheets in order to make the watertight joints required has prevented its adoption. It is necessary for the satisfactory working of such heat exchange devices that there should be no distortion of the plates, that the adj acent sinuosities of the two opposed plates should follow each other uniformly and closely, and that the surface should be free from local imperfections such as raised or hollow spots; otherwise the liquid does not flow evenly over the whole surface, for example, it does not flow over the raised parts of the surface which are thus inoperative, or it falls from them in drops Specification of Letters Patent.

AND THE LIKE.

Patented July 25', 1922.

instead of adhering as a film. WVhen, however, it is attempted to weld autogenously in the known manner the edges of the two sheets so as to make a wa-' tertight joint, the expansion of the metal under the action of the blow-pipe flame causes warping and distortion to occur and when the joints are completed the surfaces in their neighbourhood-exhibit imperfections of the kind referred to.

According to the present invention in the construction of heat exchange devices of the type referred to from sheets of aluminium arranged parallel to one another and spaced ashort distance, for example, i to 6 millimetres apart, there is inserted between the sheets near the edges to be joined an aluminium wire or rod of corresponding diameter bent to the same contour as and snugly fitting between the sheets. The two sheets thus spaced apart and firmly held, as, for example, by tacking at suitable intervals in the Jknown manner, are then welded together autogenously along the edges to form awatertight joint, the presence of the wire or rod rendering the operation comparatively easy. Distortion and blemishes of the kind above referred to are thus avoided and the joints have a pleasing appearance. The presence of the wire of rod imparts rigidity to the finished article.

The space between the sheets and the diameter of the wire or rod may be chosen according to the velocity at which it is desired the cooling liquid shall flow through them. kg

The invention although herein described as applied to sheets of aluminium may also be applied to sheets of other metals or alloys which like aluminium are suitable for the construction of heat exchange devices and. are capable of being autogenously welded but offer difficulties under the action of the blow pipe similar to those offered by aluminium when attempts are made to weld them without the interposition of a wire or rod as aforesaid.

The invention is illustrated in the accompanying drawing, Figure 1 of which is a vertical section through a heat exchange device, Figure 2 a side view with one side of the casing removed, Figure 3 a part plan and part horizontal section and Figure l a part vertical section.

A, A, are two corrugated metal sheets and cooling liquid may be suppliedhas a series i of holes formed in it through which the liqurd can use into the space between the sheets A,-while the upper pipe G has likewise a sc ries 01 holes in itso thatthe liquid may pass from the space between the sheets into the pipe and so away.

The cooling body composed of the sheets and pipes is mounted in a vertical casing D at the top of which is a trough E having'in it perforations F through which the liquid which is to be cooled and which is delivered to the trough can flow on to the top of the upper pipe C and then down the outer surfaces of the two sheets A into a trough G at the bottom.

What I claim is In a heat exchange device, the combination of a pair of corrugated metal sheets, wires of the same-metal fitting between the corrugations at opposite edges oi the sheets, the sheets and the wires being welded togGlillGI',iLI1d pipes welded to the other edges of'the sheets and having in them orifices communicating with the space between the sheets.-

In testimony that I claim the foregoing to be-my invention, I have signed my name this 15th day of June, 1921.

MAX. GRUBENMANN. 

